SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'eaa44e80b2992c546e874641d6385146346f57f011913d30b1f8ee270dab0ced' 
  AND token = 'DHbHu0ZLr1L4XjWDFn9xjf1gPKMY0fdUWt1xzxbxlJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}